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Experimental measurements for the effect of dilution procedure in blood esterases as animals biomarker for exposure to OP compounds.

Abass KS - Biomed Res Int (2014)

Bottom Line: It is unclear from the literature whether it is the carboxylesterase affinity for the organophosphate and/or the number of carboxylesterase molecules that is the dominant factor in determining the protective potential of carboxylesterase.Point estimates (concentrations calculated to produce 20, 50, and 80% inhibition) were compared across conditions and served as a measure of esterase-mediated detoxification.Results with well-known inhibitors (malathion) were in agreement with the literature, serving to support the use of this assay.

View Article: PubMed Central - PubMed

Affiliation: Department of Basic Nursing Sciences, College of Nursing, University of Kirkuk, Kirkuk, Iraq.

ABSTRACT
Organophosphate compounds can bind to carboxylesterase, which may lower the concentration of organophosphate pesticides at the target site enzyme, cholinesterase. It is unclear from the literature whether it is the carboxylesterase affinity for the organophosphate and/or the number of carboxylesterase molecules that is the dominant factor in determining the protective potential of carboxylesterase. The fundamental dilutions and kinetic effects of esterase enzyme are still poorly understood. This study aims to confirm and extend our current knowledge about the effects of dilutions on esterases activities in the blood for birds with respect to protecting the enzyme from organophosphate inhibition. There was significantly higher esterases activities in dilution 1 : 10 in the all blood samples from quail, duck, and chick compared to other dilutions (1 : 5, 1 : 15, 1 : 20, and 1 : 25) in all cases. Furthermore, our results also pointed to the importance of estimating different dilutions effects prior to using in birds as biomarker tools of environmental exposure. Concentration-inhibition curves were determined for the inhibitor in the presence of dilutions 1 : 5, 1 : 10, plus 1 : 15 (to stimulate carboxylesterase). Point estimates (concentrations calculated to produce 20, 50, and 80% inhibition) were compared across conditions and served as a measure of esterase-mediated detoxification. Results with well-known inhibitors (malathion) were in agreement with the literature, serving to support the use of this assay. Among the thiol-esters dilution 1 : 5 was observed to have the highest specificity constant (k(cat)/K(m)), and the K m and k cat values were 176 ΞΌM and 16,765 s(-1), respectively, for S-phenyl thioacetate ester, while detected in dilution 1: 15 was the lowest specificity constant (k(cat)/K(m)), and the Km and k cat values were 943 ΞΌM and 1154 s(-1), respectively, for acetylthiocholine iodide ester.

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Regression analyses between CbE and ChE activities in all tested birds for plasma, serum, and erythrocyte across different dilutions (1 : 5, 1 : 10, 1 : 15, 1 : 20, and 1 : 25).
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fig6: Regression analyses between CbE and ChE activities in all tested birds for plasma, serum, and erythrocyte across different dilutions (1 : 5, 1 : 10, 1 : 15, 1 : 20, and 1 : 25).

Mentions: Blood from erythrocyte was seen significant (P < 0.05) within dilution 1 : 25 among other dilutions for quail CbE and chick ChE (Figures 3(a) and 3(c)) and was seen not significant (P > 0.05) between dilution 1 : 20 and dilution 1 : 20 for duck (Figure 3(b)), while there were significant (P < 0.05) differences within dilution 1 : 25 among other dilutions used for chick CbE and ChE (Figure 3). ChE was seen not significant (P > 0.05) between dilution 1 : 20 and dilution 1 : 25 for quail (Figure 3(a)); erythrocyte activities of CbE ranged between 50.1 and 850.6 nmol minβˆ’1 mLβˆ’1 for quail, between 68.4 and 318.8 nmol minβˆ’1 mLβˆ’1 for duck, and between 184.2 and 904.7 nmol minβˆ’1 mLβˆ’1 for chick samples across different dilutions, whereas for erythrocyte ChE ranged between 35.3 and 996.4 nmol minβˆ’1 mLβˆ’1 for quail, between 42.3 and 293.5 nmol minβˆ’1 mLβˆ’1 for duck, and between 65.4 and 516.4 nmol minβˆ’1 mLβˆ’1 for chick samples across different dilutions (Figures 3(a)–3(c)). Overall study, the dilution 1 : 25 gave a lowest enzymatic activity in both CbE and ChE (Figures 1–3). The distribution of the mean individuals values of esterase enzyme activity in all birds and blood contents in different dilutions was detected the highest esterase activities in ChE (318.7 nmol minβˆ’1 mLβˆ’1) compared to CbE (214.4 nmol minβˆ’1 mLβˆ’1) (Figure 4). In all cases (quail, duck, and chick used five dilutions), the linear regression found between CbE and ChE was seen to be R2 = 0.114, P < 0.218 for quail; R2 = 0.641, P < 0.0003 for duck; and R2 = 0.767, P < 0.0007 for chick (Figure 5). In addition, the author found a linear regression between all tested blood samples (R2 = 0.812, P < 0.0001 for plasma; R2 = 0.694, P < 0.0001 for serum; andR2 = 0.391, P < 0.0126 for erythrocyte) (Figure 6). The author found blood dilution only with erythrocyte detects in higher activities of CbE and ChE than plasma and serum (Figure 7). Pearson correlation coefficient (r) calculated to measure the degree of relationship between CbE and ChE in the plasma, serum, and erythrocyte for testing birds was observed significantly in plasma, serum, and erythrocyte with dilution 1 : 10 for quail and chick, in addition to a significant effect with dilution 1 : 20 for serum of quail and duck (Table 1).


Experimental measurements for the effect of dilution procedure in blood esterases as animals biomarker for exposure to OP compounds.

Abass KS - Biomed Res Int (2014)

Regression analyses between CbE and ChE activities in all tested birds for plasma, serum, and erythrocyte across different dilutions (1 : 5, 1 : 10, 1 : 15, 1 : 20, and 1 : 25).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4016918&req=5

fig6: Regression analyses between CbE and ChE activities in all tested birds for plasma, serum, and erythrocyte across different dilutions (1 : 5, 1 : 10, 1 : 15, 1 : 20, and 1 : 25).
Mentions: Blood from erythrocyte was seen significant (P < 0.05) within dilution 1 : 25 among other dilutions for quail CbE and chick ChE (Figures 3(a) and 3(c)) and was seen not significant (P > 0.05) between dilution 1 : 20 and dilution 1 : 20 for duck (Figure 3(b)), while there were significant (P < 0.05) differences within dilution 1 : 25 among other dilutions used for chick CbE and ChE (Figure 3). ChE was seen not significant (P > 0.05) between dilution 1 : 20 and dilution 1 : 25 for quail (Figure 3(a)); erythrocyte activities of CbE ranged between 50.1 and 850.6 nmol minβˆ’1 mLβˆ’1 for quail, between 68.4 and 318.8 nmol minβˆ’1 mLβˆ’1 for duck, and between 184.2 and 904.7 nmol minβˆ’1 mLβˆ’1 for chick samples across different dilutions, whereas for erythrocyte ChE ranged between 35.3 and 996.4 nmol minβˆ’1 mLβˆ’1 for quail, between 42.3 and 293.5 nmol minβˆ’1 mLβˆ’1 for duck, and between 65.4 and 516.4 nmol minβˆ’1 mLβˆ’1 for chick samples across different dilutions (Figures 3(a)–3(c)). Overall study, the dilution 1 : 25 gave a lowest enzymatic activity in both CbE and ChE (Figures 1–3). The distribution of the mean individuals values of esterase enzyme activity in all birds and blood contents in different dilutions was detected the highest esterase activities in ChE (318.7 nmol minβˆ’1 mLβˆ’1) compared to CbE (214.4 nmol minβˆ’1 mLβˆ’1) (Figure 4). In all cases (quail, duck, and chick used five dilutions), the linear regression found between CbE and ChE was seen to be R2 = 0.114, P < 0.218 for quail; R2 = 0.641, P < 0.0003 for duck; and R2 = 0.767, P < 0.0007 for chick (Figure 5). In addition, the author found a linear regression between all tested blood samples (R2 = 0.812, P < 0.0001 for plasma; R2 = 0.694, P < 0.0001 for serum; andR2 = 0.391, P < 0.0126 for erythrocyte) (Figure 6). The author found blood dilution only with erythrocyte detects in higher activities of CbE and ChE than plasma and serum (Figure 7). Pearson correlation coefficient (r) calculated to measure the degree of relationship between CbE and ChE in the plasma, serum, and erythrocyte for testing birds was observed significantly in plasma, serum, and erythrocyte with dilution 1 : 10 for quail and chick, in addition to a significant effect with dilution 1 : 20 for serum of quail and duck (Table 1).

Bottom Line: It is unclear from the literature whether it is the carboxylesterase affinity for the organophosphate and/or the number of carboxylesterase molecules that is the dominant factor in determining the protective potential of carboxylesterase.Point estimates (concentrations calculated to produce 20, 50, and 80% inhibition) were compared across conditions and served as a measure of esterase-mediated detoxification.Results with well-known inhibitors (malathion) were in agreement with the literature, serving to support the use of this assay.

View Article: PubMed Central - PubMed

Affiliation: Department of Basic Nursing Sciences, College of Nursing, University of Kirkuk, Kirkuk, Iraq.

ABSTRACT
Organophosphate compounds can bind to carboxylesterase, which may lower the concentration of organophosphate pesticides at the target site enzyme, cholinesterase. It is unclear from the literature whether it is the carboxylesterase affinity for the organophosphate and/or the number of carboxylesterase molecules that is the dominant factor in determining the protective potential of carboxylesterase. The fundamental dilutions and kinetic effects of esterase enzyme are still poorly understood. This study aims to confirm and extend our current knowledge about the effects of dilutions on esterases activities in the blood for birds with respect to protecting the enzyme from organophosphate inhibition. There was significantly higher esterases activities in dilution 1 : 10 in the all blood samples from quail, duck, and chick compared to other dilutions (1 : 5, 1 : 15, 1 : 20, and 1 : 25) in all cases. Furthermore, our results also pointed to the importance of estimating different dilutions effects prior to using in birds as biomarker tools of environmental exposure. Concentration-inhibition curves were determined for the inhibitor in the presence of dilutions 1 : 5, 1 : 10, plus 1 : 15 (to stimulate carboxylesterase). Point estimates (concentrations calculated to produce 20, 50, and 80% inhibition) were compared across conditions and served as a measure of esterase-mediated detoxification. Results with well-known inhibitors (malathion) were in agreement with the literature, serving to support the use of this assay. Among the thiol-esters dilution 1 : 5 was observed to have the highest specificity constant (k(cat)/K(m)), and the K m and k cat values were 176 ΞΌM and 16,765 s(-1), respectively, for S-phenyl thioacetate ester, while detected in dilution 1: 15 was the lowest specificity constant (k(cat)/K(m)), and the Km and k cat values were 943 ΞΌM and 1154 s(-1), respectively, for acetylthiocholine iodide ester.

Show MeSH
Related in: MedlinePlus